header{
    width: 100%;
    position:fixed;
    background: #fff;
    z-index: 999;
    top:0px;
}
nav{
    display: flex;
    align-items: center;
    height: 70px;
    justify-content: space-between;
}
nav img{
    width: 170px;
    height:50px;
}
nav ul {
    display: flex;
}
nav ul li a.active{
    background: #36c7d1;
    color: #fff;
}
nav ul li a{
    display: inline-block;
    width: 130px;
    height: 70px;
    line-height: 70px;
    text-align: center;
    color: #666;
    transition: .3s;
}
nav ul li a:hover{
    color: #fff;
    background: #36c7d1;
}